1. Field of the Disclosure
The present disclosure relates generally to inkjet printheads, and more particularly, to a priming system for inkjet printheads.
2. Description of the Related Art
A typical inkjet printhead includes a heater chip having a nozzle plate either attached to or integrated with the heater chip. The heater chip is supported on a substrate. The inkjet printhead also includes one or more ink chambers/tanks that supply ink to the heater chip and the nozzle plate for printing/priming purposes.
It has been observed that there is an increasing demand for a use of smaller ink drop sizes as well as pigmented inks for printing purposes. However, the use of the smaller ink drop sizes and the pigmented inks may be associated with problems, such as a deterioration in idle time for an inkjet printhead. The term, ‘idle time,’ as used herein relates to a print quality defect that is caused by evaporation of water from the nozzles of an inkjet printhead during the period of non-printing. Further, the occurrence of the idle time defect may result in droplet misdirection, erratic printing, and missing nozzles. Also, a typical inkjet printhead may have nozzles configured to eject ink in a downward direction, and accordingly, a pigmented ink is more likely to settle towards the bottom portion of the inkjet printhead or an ink tank when the inkjet printhead is sitting idle. Further, the settlement of the pigmented ink is again associated with a deterioration in idle time and other startup issues. Furthermore, the pigment loading in the ink may vary throughout the life of an inkjet printhead/tank, and the difference in pigment loading may negatively affect the consistency of optical density, thus adding to the problems associated with the settlement of the pigmented ink. The affect of idle time on print quality may be masked by frequent maintenance, such as by frequently priming/purging ink through an inkjet printhead, or by frequent nozzle spits between printed swaths.
Priming/purging is considered to be a critical maintenance step to remove trapped air bubbles, ink and any other contaminants from within the inkjet printhead, in order to facilitate the inkjet printhead to operate properly without misprinting and to achieve a high print resolution. However, it has been observed that frequent maintenance may still be unable to facilitate an inkjet printhead to perform optimally. Further, most priming systems that are known in the art may be cost-ineffective and incapable of efficiently priming an inkjet printhead. Furthermore, a large volume of ink may get wasted when being used for priming, purging, or spitting of an inkjet printhead.
Accordingly, there persists a need for an effective priming system for inkjet printheads in order to overcome the drawbacks and limitations of prior art priming systems. Specifically, there persists a need for a priming system that is cost-effective and averts any wastage of ink required to prime/purge an inkjet printhead.